html,
body {
  height: 100%;
}

body {
  display: flex;
  align-items: center;
  padding-top: 40px;
  padding-bottom: 40px;
  background-color: #f5f5f5;
}

.form-signin {
  width: 100%;
  max-width: 330px;
  padding: 15px;
  margin: auto;
}

.form-signin .checkbox {
  font-weight: 400;
}

.form-signin .form-floating:focus-within {
  z-index: 2;
}

.form-signin input[type="email"] {
  margin-bottom: -1px;
  border-bottom-right-radius: 0;
  border-bottom-left-radius: 0;
}

.form-signin input[type="password"] {
  margin-bottom: 10px;
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}
.father1 {
  width: 300px;
  height: 400px;//修改这里即可
border: 1px solid black;
  margin: 20px auto;
  position: relative;
  display: block;
  overflow: hidden;


}

.father1>img {
  position: absolute;
  top: 50%;
  left: 50%;
  display: block;
  transform: translate(-50%, -50%);
  height: 100%;
}
